SDS gel electrophoresis is used extensively to separate and identify denatured
proteins. However, because this method relies on protein size alone, little
information about proteins with the same molecular weight can be obtained.
Peptide mapping is one of a number of techniques used to study the relatedness
of similarly sized proteins. With this method, proteases are used to cut
proteins into smaller peptide fragments and the fragments derived from two or
more proteins are compared. The number and size of fragments generated from a
protein are determined largely by the protein’s amino acid sequence, since
proteases break peptide bonds adjacent to preferred amino acid residues. In this
exercise, students use peptide mapping to compare the structural relatedness of
serum albumin from the human, cow, chicken and pigeon. Typical results of the
exercise are shown below. Includes human, cow, chicken and pigeon albumins,
standard proteins, sample buffer and chymotrypsin. Requires four 12 well gels
for 8 groups of students or two gels for 6 groups.
Click Here for polyacryamide
electrophoresis packages and gels.
Modern
Biology Inc